Effects of alpha,beta-unsaturated sulphones and phosphonium salts on ecto-ATPase activity and contractile responses mediated via P2 chi-purinoceptors.

1. In the guinea-pig urinary bladder and vas deferens, several alpha,beta-unsaturated sulphones and phosphonium salts that were tested inhibited ecto-ATPase activity. The sulphones were more active in the bladder but the phosphonium salts were more effective in the vas deferens. 2. These compounds either potentiated or inhibited purinergic contractile responses in the guinea-pig urinary bladder and vas deferens. 3. alpha,beta-Unsaturated sulphones and phosphonium salts represent a new promising class of compounds, capable of modulating purinergic neurotransmission.